Thinking about it and looking at the Java driver, it may be better to use Map[String, Any]:

jsScope: Option[Map[String, Any]]

For backwards compatibility, this needs to be a Type Class to take both Strings and DBObjects.

Hi,

Thank you for the great Scala driver.
I'm using this for my production service :)

For backwards compatibility, this needs to be a Type Class to take both Strings and DBObjects.

Excuse me, but do you really want backward compatibility here?
Can't we just make it use DBObject as troger originally suggested?

First of all, the current implementation jsScope: Option[String] is not working at all: Basically, it must be an Option[DBObject] or an Option[Map[_, _]] to properly serialized to a JavaScript object, as the original mapReduce comand's scope parameter expects.
In other words, all the users passing Option[String]s would be encountering the bug that the scope variables are totally missing from scope - as troger reported.
Now, shouldn't the users be notified with compile errors for passing jsScope an Option[String]?

Also, how do you implement the type class serializes a String like """{ testVar: true }""" to a DBObject or a Map?
Parsing JSON manually?

This has been fixed in 2.6.1 - apologies for the delay